:root {
    --primary-bg:
        radial-gradient(circle at 16% 12%, rgba(96, 165, 250, 0.2), transparent 28%),
        radial-gradient(circle at 84% 18%, rgba(59, 130, 246, 0.16), transparent 30%),
        radial-gradient(circle at 45% 92%, rgba(16, 185, 129, 0.1), transparent 28%),
        linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    --secondary-bg: rgba(255, 255, 255, 0.66);
    --card-bg: rgba(255, 255, 255, 0.74);
    --glass-strong: rgba(255, 255, 255, 0.82);
    --glass-soft: rgba(255, 255, 255, 0.48);
    --text-primary: #1a202c;
    --text-secondary: #4a5568;
    --text-muted: #718096;
    --border-color: rgba(148, 163, 184, 0.22);
    --glass-border: rgba(255, 255, 255, 0.76);
    --accent-primary: #3b82f6;
    --accent-secondary: #60a5fa;
    --accent-success: #10b981;
    --accent-danger: #ef4444;
    --shadow-light: 0 10px 24px rgba(15, 23, 42, 0.08);
    --shadow-medium: 0 18px 38px rgba(59, 130, 246, 0.2), 0 6px 16px rgba(15, 23, 42, 0.08);
    --shadow-heavy: 0 34px 90px rgba(15, 23, 42, 0.16), 0 12px 28px rgba(59, 130, 246, 0.1);
    --inner-highlight: inset 0 1px 0 rgba(255, 255, 255, 0.92);
    --inner-depth: inset 0 -18px 42px rgba(96, 165, 250, 0.05);
    --blur-light: blur(14px);
    --blur-medium: blur(26px);
    --safe-bottom: env(safe-area-inset-bottom, 0px);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html,
body {
    min-height: 100%;
    overflow: hidden;
}

body {
    position: relative;
    min-height: 100dvh;
    background: var(--primary-bg);
    color: var(--text-primary);
    font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    font-size: 14px;
    line-height: 1.5;
}

body::before,
body::after {
    content: "";
    position: fixed;
    z-index: -1;
    pointer-events: none;
    filter: blur(4px);
}

body::before {
    inset: 4% auto auto 7%;
    width: 18rem;
    height: 18rem;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(96, 165, 250, 0.22), transparent 68%);
}

body::after {
    right: 5%;
    bottom: 5%;
    width: 22rem;
    height: 22rem;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.16), transparent 68%);
}

button,
input,
textarea {
    font: inherit;
}

button {
    border: 0;
}

.is-hidden {
    display: none !important;
}

.app-shell {
    display: grid;
    grid-template-columns: minmax(320px, 450px) minmax(0, 760px);
    gap: 1rem;
    width: min(1240px, calc(100vw - 2rem));
    height: calc(100dvh - 2rem);
    max-height: 900px;
    margin: 1rem auto;
    perspective: 1400px;
}

.connect-screen,
.chat-screen {
    position: relative;
    min-height: 0;
    background: var(--card-bg);
    border: 1px solid var(--glass-border);
    border-radius: 28px;
    box-shadow: var(--shadow-heavy), var(--inner-highlight), var(--inner-depth);
    backdrop-filter: var(--blur-medium);
    -webkit-backdrop-filter: var(--blur-medium);
    transform-style: preserve-3d;
}

.connect-screen::before,
.chat-screen::before {
    content: "";
    position: absolute;
    inset: 1px;
    z-index: -1;
    border-radius: inherit;
    background:
        linear-gradient(145deg, rgba(255, 255, 255, 0.74), rgba(255, 255, 255, 0.18) 42%, rgba(96, 165, 250, 0.08)),
        radial-gradient(circle at 18% 0%, rgba(255, 255, 255, 0.95), transparent 28%);
    pointer-events: none;
}

.connect-screen {
    display: flex;
    flex-direction: column;
    gap: clamp(1rem, 2dvh, 1.6rem);
    min-height: 0;
    overflow-y: auto;
    overscroll-behavior: contain;
    padding: clamp(1.25rem, 3vw, 2.4rem);
    scrollbar-gutter: stable;
    transform: rotateY(0.5deg) translateZ(0);
}

.chat-screen {
    overflow: hidden;
    transform: rotateY(-0.35deg) translateZ(0);
}

.connect-screen::-webkit-scrollbar {
    width: 6px;
}

.connect-screen::-webkit-scrollbar-track {
    background: transparent;
}

.connect-screen::-webkit-scrollbar-thumb {
    border-radius: 999px;
    background: rgba(100, 116, 139, 0.24);
}

.brand-bar {
    display: flex;
    align-items: center;
    gap: 0.9rem;
}

.brand-mark {
    display: grid;
    place-items: center;
    width: 52px;
    height: 52px;
    border-radius: 18px;
    color: white;
    background:
        radial-gradient(circle at 30% 22%, rgba(255, 255, 255, 0.55), transparent 18%),
        linear-gradient(145deg, var(--accent-secondary), var(--accent-primary) 58%, #2563eb);
    box-shadow:
        0 18px 34px rgba(59, 130, 246, 0.24),
        inset 0 1px 0 rgba(255, 255, 255, 0.45),
        inset 0 -10px 22px rgba(37, 99, 235, 0.28);
    font-size: 1.55rem;
}

.brand-bar h1 {
    font-size: clamp(1.65rem, 3vw, 2rem);
    line-height: 1.1;
}

.brand-bar p,
.welcome-copy p,
.connect-tip,
.room-meta p {
    color: var(--text-secondary);
}

.welcome-art {
    position: relative;
    display: grid;
    place-items: center;
    width: min(58vw, 250px);
    aspect-ratio: 1;
    margin: 0.5rem auto 0;
    border-radius: 50%;
    background:
        radial-gradient(circle at 30% 22%, rgba(255, 255, 255, 0.86), transparent 24%),
        radial-gradient(circle at 38% 42%, rgba(16, 185, 129, 0.12), transparent 18%),
        radial-gradient(circle at 70% 20%, rgba(96, 165, 250, 0.16), transparent 9%),
        linear-gradient(145deg, rgba(59, 130, 246, 0.08), rgba(96, 165, 250, 0.06));
    border: 1px solid rgba(255, 255, 255, 0.7);
    box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.86),
        inset 18px 24px 42px rgba(255, 255, 255, 0.48),
        0 22px 48px rgba(59, 130, 246, 0.1);
}

.welcome-art::before,
.welcome-art::after {
    content: "";
    position: absolute;
    border-radius: 50%;
    background: var(--accent-secondary);
    opacity: 0.65;
}

.welcome-art::before {
    width: 8px;
    height: 8px;
    right: 17%;
    top: 28%;
}

.welcome-art::after {
    width: 10px;
    height: 10px;
    left: 16%;
    bottom: 26%;
    background: var(--accent-primary);
}

.bubble {
    position: absolute;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.8rem;
    border-radius: 28px;
}

.bubble span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.bubble-primary {
    left: 16%;
    top: 30%;
    width: 128px;
    height: 78px;
    color: white;
    background:
        radial-gradient(circle at 28% 18%, rgba(255, 255, 255, 0.55), transparent 20%),
        linear-gradient(145deg, var(--accent-secondary), var(--accent-primary) 62%, #2563eb);
    box-shadow:
        0 18px 30px rgba(59, 130, 246, 0.26),
        inset 0 1px 0 rgba(255, 255, 255, 0.4),
        inset 0 -12px 24px rgba(37, 99, 235, 0.22);
    animation: floatPrimary 5.5s ease-in-out infinite;
}

.bubble-primary::after {
    content: "";
    position: absolute;
    left: 28px;
    bottom: -18px;
    border-top: 24px solid var(--accent-primary);
    border-right: 24px solid transparent;
}

.bubble-primary span {
    background: white;
}

.bubble-secondary {
    right: 12%;
    bottom: 23%;
    width: 126px;
    height: 72px;
    background: rgba(255, 255, 255, 0.86);
    backdrop-filter: var(--blur-light);
    -webkit-backdrop-filter: var(--blur-light);
    box-shadow:
        0 20px 42px rgba(15, 23, 42, 0.11),
        inset 0 1px 0 rgba(255, 255, 255, 0.95);
    animation: floatSecondary 6.2s ease-in-out infinite;
}

.bubble-secondary::after {
    content: "";
    position: absolute;
    right: 24px;
    bottom: -16px;
    border-top: 22px solid white;
    border-left: 22px solid transparent;
}

.bubble-secondary span {
    background: #60a5fa;
}

@keyframes floatPrimary {
    0%,
    100% {
        transform: translate3d(0, 0, 22px);
    }

    50% {
        transform: translate3d(0, -8px, 28px);
    }
}

@keyframes floatSecondary {
    0%,
    100% {
        transform: translate3d(0, 0, 34px);
    }

    50% {
        transform: translate3d(5px, 7px, 40px);
    }
}

.welcome-copy {
    text-align: center;
}

.welcome-copy h2 {
    margin-bottom: 0.35rem;
    font-size: clamp(1.45rem, 3vw, 1.8rem);
}

.welcome-copy p {
    max-width: 25rem;
    margin: 0 auto;
    font-size: 1rem;
}

.connection-form {
    display: grid;
    gap: 1rem;
}

.input-group {
    display: grid;
    gap: 0.5rem;
}

.input-group label {
    color: #64748b;
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.field-shell {
    display: grid;
    grid-template-columns: 48px minmax(0, 1fr) 30px;
    align-items: center;
    min-height: 64px;
    padding: 0 0.8rem;
    border: 1px solid rgba(255, 255, 255, 0.72);
    border-radius: 18px;
    background: rgba(255, 255, 255, 0.62);
    box-shadow:
        0 12px 28px rgba(15, 23, 42, 0.06),
        inset 0 1px 0 rgba(255, 255, 255, 0.88);
    backdrop-filter: var(--blur-light);
    -webkit-backdrop-filter: var(--blur-light);
    transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.field-shell:focus-within {
    border-color: rgba(96, 165, 250, 0.76);
    box-shadow:
        0 18px 38px rgba(59, 130, 246, 0.14),
        0 0 0 4px rgba(59, 130, 246, 0.08),
        inset 0 1px 0 rgba(255, 255, 255, 0.92);
    transform: translateY(-1px);
}

.field-shell > i:first-child {
    display: grid;
    place-items: center;
    width: 38px;
    height: 38px;
    border-radius: 14px;
    color: var(--accent-secondary);
    background: rgba(96, 165, 250, 0.12);
}

.field-shell input {
    min-width: 0;
    border: 0;
    outline: 0;
    background: transparent;
    color: var(--text-primary);
    font-size: 1rem;
}

.field-check {
    display: grid;
    place-items: center;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    color: white;
    background: var(--accent-success);
    font-size: 0.72rem;
    opacity: 0;
    transform: scale(0.8);
    transition: opacity 0.2s ease, transform 0.2s ease;
}

.field-shell.has-value .field-check {
    opacity: 1;
    transform: scale(1);
}

.btn,
.icon-btn,
.send-btn {
    cursor: pointer;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    min-height: 60px;
    padding: 0 1.2rem;
    border-radius: 18px;
    color: white;
    font-size: 1.05rem;
    font-weight: 800;
    background:
        radial-gradient(circle at 35% 10%, rgba(255, 255, 255, 0.45), transparent 18%),
        linear-gradient(145deg, var(--accent-secondary), var(--accent-primary) 58%, #2563eb);
    box-shadow:
        0 22px 44px rgba(59, 130, 246, 0.28),
        inset 0 1px 0 rgba(255, 255, 255, 0.45),
        inset 0 -12px 24px rgba(37, 99, 235, 0.26);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover,
.send-btn:hover,
.icon-btn:hover {
    transform: translateY(-2px);
}

.field-shell,
.btn,
.icon-btn,
.send-btn,
.message,
.user-list li {
    will-change: transform;
}

.btn:active,
.send-btn:active,
.icon-btn:active {
    transform: translateY(0);
}

.status {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    min-height: 56px;
    padding: 0.8rem 1rem;
    border-radius: 18px;
    font-weight: 700;
    backdrop-filter: var(--blur-light);
    -webkit-backdrop-filter: var(--blur-light);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.78);
}

.status.neutral {
    color: var(--text-muted);
    background: rgba(255, 255, 255, 0.68);
    border: 1px solid var(--border-color);
}

.status.connected {
    color: #059669;
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.18);
}

.status.disconnected {
    color: var(--accent-danger);
    background: rgba(239, 68, 68, 0.08);
    border: 1px solid rgba(239, 68, 68, 0.16);
}

.connect-tip {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    margin-top: auto;
    padding: 1rem;
    border-radius: 18px;
    background: linear-gradient(135deg, rgba(96, 165, 250, 0.12), rgba(255, 255, 255, 0.54));
    border: 1px solid rgba(255, 255, 255, 0.66);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.76), 0 12px 26px rgba(15, 23, 42, 0.05);
}

.connect-tip i {
    color: var(--accent-secondary);
    font-size: 1.35rem;
}

.chat-screen {
    display: flex;
    flex-direction: column;
}

.chat-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.15rem 1.25rem;
    color: white;
    background:
        radial-gradient(circle at 12% 0%, rgba(255, 255, 255, 0.28), transparent 28%),
        linear-gradient(145deg, var(--accent-primary), var(--accent-secondary));
    box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.24),
        0 16px 34px rgba(59, 130, 246, 0.18);
}

.room-meta {
    min-width: 0;
    flex: 1;
}

.room-meta h2 {
    overflow: hidden;
    font-size: 1.3rem;
    line-height: 1.2;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.room-meta p {
    display: flex;
    align-items: center;
    gap: 0.45rem;
    color: rgba(255, 255, 255, 0.86);
}

.online-dot {
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--accent-success);
    box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.18);
}

.chat-actions {
    display: flex;
    align-items: center;
    gap: 0.65rem;
}

.icon-btn {
    display: inline-grid;
    place-items: center;
    width: 46px;
    height: 46px;
    border-radius: 50%;
    color: inherit;
    background: rgba(255, 255, 255, 0.18);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.22), 0 10px 22px rgba(37, 99, 235, 0.12);
    backdrop-filter: var(--blur-light);
    -webkit-backdrop-filter: var(--blur-light);
    transition: transform 0.2s ease, background-color 0.2s ease, box-shadow 0.2s ease;
}

.icon-btn:hover {
    background: rgba(255, 255, 255, 0.24);
}

.mobile-back-btn,
.users-close {
    display: none;
}

.chat-body {
    display: grid;
    grid-template-columns: 240px minmax(0, 1fr);
    min-height: 0;
    flex: 1;
}

.users-panel {
    display: flex;
    flex-direction: column;
    min-height: 0;
    border-right: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.46);
    backdrop-filter: var(--blur-light);
    -webkit-backdrop-filter: var(--blur-light);
}

.users-panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.users-panel-header h3 {
    font-size: 1rem;
}

.user-list {
    display: grid;
    gap: 0.55rem;
    padding: 1rem;
    overflow-y: auto;
    list-style: none;
}

.user-list li {
    display: flex;
    align-items: center;
    gap: 0.7rem;
    min-width: 0;
    padding: 0.75rem;
    border-radius: 14px;
    color: var(--text-secondary);
    border: 1px solid rgba(255, 255, 255, 0.68);
    background: rgba(255, 255, 255, 0.62);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.72), 0 8px 18px rgba(15, 23, 42, 0.04);
}

.user-list li::before {
    content: "";
    flex: 0 0 auto;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--accent-success);
}

.empty-users {
    padding: 0 1rem 1rem;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.messages-wrap {
    display: flex;
    flex-direction: column;
    min-width: 0;
    min-height: 0;
    background:
        radial-gradient(circle at 78% 24%, rgba(96, 165, 250, 0.08), transparent 28%),
        radial-gradient(circle at 28% 76%, rgba(16, 185, 129, 0.06), transparent 24%),
        rgba(255, 255, 255, 0.18);
}

.messages {
    display: flex;
    flex: 1;
    flex-direction: column;
    gap: 1rem;
    min-height: 0;
    padding: 1.25rem;
    overflow-y: auto;
    scroll-behavior: smooth;
}

.messages::-webkit-scrollbar,
.user-list::-webkit-scrollbar {
    width: 6px;
}

.messages::-webkit-scrollbar-track,
.user-list::-webkit-scrollbar-track {
    background: transparent;
}

.messages::-webkit-scrollbar-thumb,
.user-list::-webkit-scrollbar-thumb {
    border-radius: 999px;
    background: rgba(100, 116, 139, 0.28);
}

.message {
    max-width: min(72%, 33rem);
    padding: 0.95rem 1.1rem;
    border: 1px solid rgba(255, 255, 255, 0.68);
    border-radius: 18px 18px 18px 6px;
    background: rgba(255, 255, 255, 0.72);
    box-shadow:
        0 14px 28px rgba(15, 23, 42, 0.08),
        inset 0 1px 0 rgba(255, 255, 255, 0.82);
    backdrop-filter: var(--blur-light);
    -webkit-backdrop-filter: var(--blur-light);
    animation: messageSlide 0.24s ease-out;
}

@keyframes messageSlide {
    from {
        opacity: 0;
        transform: translateY(8px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message.own {
    align-self: flex-end;
    border: 0;
    border-radius: 18px 18px 6px 18px;
    color: white;
    background:
        radial-gradient(circle at 24% 12%, rgba(255, 255, 255, 0.32), transparent 18%),
        linear-gradient(145deg, var(--accent-primary), var(--accent-secondary));
    box-shadow:
        0 18px 36px rgba(59, 130, 246, 0.24),
        inset 0 1px 0 rgba(255, 255, 255, 0.28);
}

.message.system {
    align-self: center;
    max-width: 92%;
    padding: 0.7rem 1rem;
    border-radius: 999px;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-style: italic;
    border: 1px solid rgba(255, 255, 255, 0.72);
    background: rgba(255, 255, 255, 0.68);
    box-shadow: 0 10px 22px rgba(15, 23, 42, 0.06), inset 0 1px 0 rgba(255, 255, 255, 0.86);
}

.message-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 0.45rem;
    font-size: 0.78rem;
}

.username {
    min-width: 0;
    overflow: hidden;
    color: var(--accent-secondary);
    font-weight: 800;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.timestamp {
    flex: 0 0 auto;
    color: var(--text-muted);
}

.message.own .username,
.message.own .timestamp {
    color: rgba(255, 255, 255, 0.88);
}

.message-content {
    overflow-wrap: anywhere;
    font-size: 1rem;
}

.file-summary {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.45rem;
}

.file-size {
    margin-bottom: 0.55rem;
    color: var(--text-muted);
    font-size: 0.82rem;
}

.message.own .file-size {
    color: rgba(255, 255, 255, 0.75);
}

.file-preview img {
    max-width: 100%;
    max-height: 220px;
    margin-top: 0.65rem;
    border-radius: 12px;
    box-shadow: var(--shadow-light);
}

.file-download {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-top: 0.75rem;
    padding: 0.5rem 0.8rem;
    border: 1px solid rgba(255, 255, 255, 0.7);
    border-radius: 999px;
    color: var(--accent-secondary);
    background: rgba(255, 255, 255, 0.62);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.78);
    font-size: 0.86rem;
    font-weight: 700;
    text-decoration: none;
}

.input-area {
    display: grid;
    grid-template-columns: 48px minmax(0, 1fr) 56px;
    gap: 0.8rem;
    align-items: end;
    padding: 1rem;
    padding-bottom: calc(1rem + var(--safe-bottom));
    border-top: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.58);
    backdrop-filter: var(--blur-medium);
    -webkit-backdrop-filter: var(--blur-medium);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.84);
}

.file-input-wrapper {
    position: relative;
}

.file-input-wrapper input[type="file"] {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
}

.file-input-label,
.send-btn {
    display: grid;
    place-items: center;
    border-radius: 50%;
}

.file-input-label {
    width: 48px;
    height: 48px;
    border: 1px solid rgba(255, 255, 255, 0.78);
    color: var(--text-secondary);
    background: rgba(255, 255, 255, 0.68);
    box-shadow: 0 10px 22px rgba(15, 23, 42, 0.06), inset 0 1px 0 rgba(255, 255, 255, 0.86);
    backdrop-filter: var(--blur-light);
    -webkit-backdrop-filter: var(--blur-light);
    cursor: pointer;
}

#messageInput {
    min-width: 0;
    min-height: 48px;
    max-height: 136px;
    padding: 0.85rem 1rem;
    resize: none;
    border: 1px solid rgba(255, 255, 255, 0.78);
    border-radius: 999px;
    outline: 0;
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.72);
    font-size: 1rem;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.92), 0 10px 24px rgba(15, 23, 42, 0.05);
    backdrop-filter: var(--blur-light);
    -webkit-backdrop-filter: var(--blur-light);
}

#messageInput:focus {
    border-color: rgba(59, 130, 246, 0.5);
    box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.1);
}

.send-btn {
    width: 56px;
    height: 56px;
    color: white;
    background:
        radial-gradient(circle at 32% 16%, rgba(255, 255, 255, 0.45), transparent 18%),
        linear-gradient(145deg, var(--accent-secondary), var(--accent-primary) 60%, #2563eb);
    box-shadow:
        0 18px 36px rgba(59, 130, 246, 0.28),
        inset 0 1px 0 rgba(255, 255, 255, 0.42),
        inset 0 -10px 20px rgba(37, 99, 235, 0.24);
    font-size: 1.15rem;
}

@media (min-width: 769px) {
    .connect-screen:hover {
        transform: rotateY(0) translateY(-2px);
    }

    .chat-screen:hover {
        transform: rotateY(0) translateY(-2px);
    }

    .app-shell.is-chatting {
        grid-template-columns: minmax(0, 1fr);
    }

    .app-shell.is-chatting .chat-screen {
        grid-column: 1 / -1;
        transform: none;
    }

    .chat-screen.is-hidden {
        display: flex !important;
    }

    .chat-screen:not(.is-connected-preview) {
        opacity: 0.96;
    }

    .chat-screen:not(.is-connected-preview) .messages::before {
        content: "Connect to a room to begin chatting.";
        margin: auto;
        color: var(--text-muted);
        font-weight: 700;
    }

    .chat-screen:not(.is-connected-preview) .input-area {
        opacity: 0.45;
        pointer-events: none;
    }
}

@media (max-width: 900px) and (min-width: 769px) {
    .app-shell {
        grid-template-columns: minmax(300px, 390px) minmax(0, 1fr);
    }

    .chat-body {
        grid-template-columns: 200px minmax(0, 1fr);
    }
}

@media (min-width: 769px) and (max-height: 860px) {
    .app-shell {
        height: calc(100dvh - 1.5rem);
        margin: 0.75rem auto;
    }

    .connect-screen {
        gap: 0.85rem;
        padding: 1.6rem;
    }

    .brand-mark {
        width: 46px;
        height: 46px;
        border-radius: 16px;
        font-size: 1.35rem;
    }

    .brand-bar h1 {
        font-size: 1.75rem;
    }

    .brand-bar p {
        font-size: 0.95rem;
    }

    .welcome-art {
        width: min(42vh, 210px);
        margin-top: 0;
    }

    .bubble-primary {
        width: 110px;
        height: 68px;
    }

    .bubble-secondary {
        width: 108px;
        height: 62px;
    }

    .welcome-copy h2 {
        font-size: 1.45rem;
    }

    .welcome-copy p {
        font-size: 0.95rem;
    }

    .connection-form {
        gap: 0.75rem;
    }

    .field-shell {
        min-height: 54px;
        border-radius: 16px;
    }

    .btn {
        min-height: 54px;
    }

    .status {
        min-height: 48px;
        padding: 0.65rem 0.9rem;
    }

    .connect-tip {
        margin-top: 0;
        padding: 0.85rem;
    }
}

@media (min-width: 769px) and (max-height: 760px) {
    .app-shell {
        height: calc(100dvh - 1rem);
        margin: 0.5rem auto;
    }

    .connect-screen {
        gap: 0.65rem;
        padding: 1.1rem 1.35rem;
    }

    .brand-mark {
        width: 42px;
        height: 42px;
        border-radius: 14px;
        font-size: 1.2rem;
    }

    .brand-bar h1 {
        font-size: 1.55rem;
    }

    .brand-bar p,
    .welcome-copy p,
    .connect-tip {
        font-size: 0.9rem;
    }

    .welcome-art {
        width: min(31vh, 170px);
    }

    .bubble {
        gap: 0.55rem;
    }

    .bubble span {
        width: 9px;
        height: 9px;
    }

    .bubble-primary {
        width: 88px;
        height: 54px;
        border-radius: 20px;
    }

    .bubble-primary::after {
        left: 20px;
        bottom: -13px;
        border-top-width: 18px;
        border-right-width: 18px;
    }

    .bubble-secondary {
        width: 88px;
        height: 50px;
        border-radius: 20px;
    }

    .bubble-secondary::after {
        right: 18px;
        bottom: -12px;
        border-top-width: 17px;
        border-left-width: 17px;
    }

    .welcome-copy h2 {
        font-size: 1.28rem;
        margin-bottom: 0.15rem;
    }

    .input-group {
        gap: 0.35rem;
    }

    .input-group label {
        font-size: 0.72rem;
    }

    .field-shell {
        grid-template-columns: 42px minmax(0, 1fr) 28px;
        min-height: 48px;
        border-radius: 14px;
    }

    .field-shell > i:first-child {
        width: 32px;
        height: 32px;
        border-radius: 12px;
    }

    .btn {
        min-height: 48px;
        border-radius: 14px;
    }

    .status {
        min-height: 44px;
        border-radius: 14px;
        font-size: 0.9rem;
    }

    .connect-tip {
        padding: 0.7rem 0.85rem;
        border-radius: 14px;
    }
}

@media (max-width: 768px) {
    body {
        background:
            radial-gradient(circle at 50% 0%, rgba(96, 165, 250, 0.22), transparent 34%),
            radial-gradient(circle at 15% 90%, rgba(59, 130, 246, 0.1), transparent 30%),
            linear-gradient(155deg, #f8fafc 0%, #e8eef7 100%);
    }

    .app-shell {
        display: block;
        width: 100vw;
        height: 100dvh;
        margin: 0;
        overflow: hidden;
    }

    .connect-screen,
    .chat-screen {
        width: 100%;
        height: 100%;
        border: 0;
        border-radius: 0;
        box-shadow: none;
        transform: none;
    }

    .connect-screen {
        gap: clamp(0.8rem, 1.65dvh, 1.05rem);
        justify-content: center;
        padding: clamp(1rem, 2.5dvh, 1.35rem) 1.05rem;
        overflow-y: auto;
        scrollbar-gutter: auto;
        background:
            radial-gradient(circle at 50% 23%, rgba(96, 165, 250, 0.14), transparent 28%),
            linear-gradient(150deg, rgba(255, 255, 255, 0.94), rgba(239, 246, 255, 0.78));
    }

    .brand-bar {
        gap: 0.7rem;
        padding-top: 0;
    }

    .brand-mark {
        width: 42px;
        height: 42px;
        border-radius: 14px;
        font-size: 1.16rem;
    }

    .brand-bar h1 {
        font-size: 1.45rem;
        letter-spacing: -0.02em;
    }

    .brand-bar p {
        font-size: 0.82rem;
    }

    .welcome-art {
        width: min(52vw, 190px);
        margin: 0.15rem auto 0;
        box-shadow:
            inset 0 1px 0 rgba(255, 255, 255, 0.9),
            inset 18px 24px 42px rgba(255, 255, 255, 0.5),
            0 26px 58px rgba(59, 130, 246, 0.14);
    }

    .bubble {
        gap: 0.5rem;
    }

    .bubble span {
        width: 9px;
        height: 9px;
    }

    .bubble-primary {
        width: 92px;
        height: 56px;
        border-radius: 21px;
    }

    .bubble-primary::after {
        left: 18px;
        bottom: -11px;
        border-top-width: 16px;
        border-right-width: 16px;
    }

    .bubble-secondary {
        width: 92px;
        height: 54px;
        border-radius: 21px;
    }

    .bubble-secondary::after {
        right: 17px;
        bottom: -10px;
        border-top-width: 15px;
        border-left-width: 15px;
    }

    .welcome-copy h2 {
        margin-bottom: 0.25rem;
        font-size: 1.42rem;
        letter-spacing: -0.02em;
    }

    .welcome-copy p {
        width: min(100%, 21rem);
        font-size: 0.9rem;
        line-height: 1.4;
    }

    .connection-form {
        gap: 0.72rem;
    }

    .input-group {
        gap: 0.36rem;
    }

    .input-group label {
        font-size: 0.7rem;
    }

    .field-shell {
        grid-template-columns: 42px minmax(0, 1fr) 28px;
        min-height: 54px;
        border-radius: 18px;
        background: rgba(255, 255, 255, 0.82);
        box-shadow:
            0 14px 30px rgba(15, 23, 42, 0.07),
            inset 0 1px 0 rgba(255, 255, 255, 0.94);
    }

    .field-shell > i:first-child {
        width: 32px;
        height: 32px;
        border-radius: 12px;
    }

    .field-shell input {
        font-size: 0.95rem;
    }

    .btn {
        min-height: 54px;
        border-radius: 18px;
        font-size: 0.98rem;
        box-shadow:
            0 18px 34px rgba(59, 130, 246, 0.26),
            inset 0 1px 0 rgba(255, 255, 255, 0.46),
            inset 0 -12px 24px rgba(37, 99, 235, 0.24);
    }

    .status {
        justify-content: center;
        min-height: 42px;
        padding: 0.58rem 0.75rem;
        border-radius: 999px;
        font-size: 0.78rem;
        text-align: center;
        line-height: 1.25;
        white-space: normal;
    }

    .connect-tip {
        gap: 0.65rem;
        margin-top: 0;
        padding: 0.72rem 0.85rem;
        border-radius: 18px;
        font-size: 0.8rem;
        line-height: 1.3;
        background: linear-gradient(135deg, rgba(96, 165, 250, 0.12), rgba(255, 255, 255, 0.74));
    }

    .connect-tip i {
        font-size: 1.1rem;
    }

    .chat-header {
        min-height: 92px;
        padding: 1rem;
        border-radius: 0 0 22px 22px;
        box-shadow: var(--shadow-medium);
    }

    .mobile-back-btn,
    .users-close {
        display: inline-grid;
    }

    .desktop-disconnect-btn {
        display: none;
    }

    .chat-body {
        display: block;
        position: relative;
        flex: 1;
        min-height: 0;
    }

    .messages-wrap {
        height: calc(100dvh - 92px);
    }

    .messages {
        padding: 1rem;
    }

    .message {
        max-width: 84%;
    }

    .message.system {
        max-width: 90%;
    }

    .users-panel {
        position: fixed;
        top: 0;
        right: 0;
        bottom: 0;
        z-index: 40;
        width: min(84vw, 320px);
        border-left: 1px solid var(--border-color);
        border-right: 0;
        background: rgba(255, 255, 255, 0.94);
        box-shadow: var(--shadow-heavy);
        transform: translateX(105%);
        transition: transform 0.24s ease;
    }

    body.users-open .users-panel {
        transform: translateX(0);
    }

    .users-close {
        color: var(--text-secondary);
        background: rgba(15, 23, 42, 0.06);
    }

    .mobile-drawer-backdrop {
        position: fixed;
        inset: 0;
        z-index: 35;
        pointer-events: none;
        background: rgba(15, 23, 42, 0);
        transition: background-color 0.24s ease;
    }

    body.users-open .mobile-drawer-backdrop {
        pointer-events: auto;
        background: rgba(15, 23, 42, 0.34);
    }

    .input-area {
        grid-template-columns: 46px minmax(0, 1fr) 52px;
        gap: 0.6rem;
        padding: 0.75rem;
        padding-bottom: calc(0.75rem + var(--safe-bottom));
    }

    .file-input-label {
        width: 46px;
        height: 46px;
    }

    .send-btn {
        width: 52px;
        height: 52px;
    }
}

@media (max-width: 420px) {
    .connect-screen {
        gap: 0.74rem;
        padding: 0.85rem 0.9rem;
    }

    .brand-bar h1 {
        font-size: 1.42rem;
    }

    .welcome-copy h2 {
        font-size: 1.32rem;
    }

    .welcome-copy p {
        font-size: 0.85rem;
    }

    .welcome-art {
        width: min(48vw, 170px);
    }

    .message {
        max-width: 90%;
        padding: 0.82rem 0.92rem;
    }

    .room-meta h2 {
        font-size: 1.15rem;
    }
}

@media (max-width: 420px) and (max-height: 700px) {
    .connect-screen {
        gap: 0.56rem;
        padding: 0.6rem 0.75rem;
    }

    .brand-mark {
        width: 38px;
        height: 38px;
        border-radius: 13px;
        font-size: 1.05rem;
    }

    .brand-bar h1 {
        font-size: 1.35rem;
    }

    .brand-bar p {
        font-size: 0.8rem;
    }

    .welcome-art {
        width: min(38vw, 132px);
    }

    .welcome-copy h2 {
        font-size: 1.18rem;
    }

    .welcome-copy p {
        font-size: 0.8rem;
    }

    .connection-form {
        gap: 0.5rem;
    }

    .field-shell {
        min-height: 46px;
        border-radius: 15px;
    }

    .btn {
        min-height: 46px;
        font-size: 0.92rem;
    }

    .status {
        min-height: 40px;
        padding: 0.5rem 0.65rem;
        font-size: 0.78rem;
    }

    .connect-tip {
        padding: 0.55rem 0.65rem;
        font-size: 0.76rem;
    }
}

@media (max-width: 360px) and (max-height: 640px) {
    .welcome-art {
        width: 110px;
    }

    .connect-tip {
        display: none;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
    }
}